Mylar® tape (¼") is used for affixing slide chips to the stereo
slide mounts. The 3/8" width is used to seal shut Spicer™
mounts. Some people use the Mylar® tape instead of ironing their
heat-seal mounts, for a "reversible" seal. The 3/8" size is
also used when aluminum masks are sealed in glass or in a cardboard foldover.

Silver metalized tape is used for masking mounted slides. Compared
to our silver Mylar® tape, it has a thicker base and is more opaque (better at
blocking light). Our black Mylar® tape also does a good job of masking
slides.